Governments in the region as well as the United States have been demanding that he be arrested for months, accusing him of having links with the terrorist network al-Qaeda.

Mr Ba'asyir is recovering in hospital in the city of
Solo after he collapsed on Friday ahead of being questioned in connection with bomb attacks on churches in 2000.

An Indonesian Foreign ministry spokesman told the BBC that the police were acting on information that alleged Mr Ba'asyir was behind previous bombings in Indonesia and even plots to kill the president.

Although under arrest, the cleric will remain in hospital until he has recovered.

At least 10 people died in the church bombings in 2000

The move came as Australia warned it had received intelligence about plans for bomb attacks on Westerners in the Indonesian capital, Jakarta.

In another development, the Indonesian Defence Minister Matori Abdul Jalil told a news conference in Bali that he still believed the al-Qaeda network was behind the night-club bombing.

However, he did not reveal his evidence.

He also said he did not anticipate any backlash against the arrest of Mr Ba'asyir.

There was a small demonstration outside the hospital where the cleric is being held, but it remained peaceful.

Senior police officials went to the hospital in Solo on Saturday morning to check that Mr Ba'asyir was in fact ill.

According to a senior Muslim leader, they then handed an arrest warrant to Mr Ba'asyir's lawyers.

Shadowy group

The cleric is suspected by some governments of leading the shadowy Jemaah Islamiah group - a charge he denies.